A liquid crystal display apparatus, such as a liquid crystal display, LCD is commonly used electronic equipment, due to its low power consumption, small size, light weight and other characteristics, so is adapted by users. A liquid crystal display generally includes an array substrate; the array substrate includes a plurality of thin film transistors, TFT distributed as array type. The quality of the thin film transistor directly affects the quality of the liquid crystal display panel. The thin film transistor includes etching stop layer in the conventional technology. The preparation of the etching stop layer typically requires to deposit the etching stop material that can stop etch on the entire layer, and then process the photomask is used, to etch partial of the entire layer of the etching stop material as the etching stop layer to cover partial of the active layer. Then a metal layer is covered on the etching stop layer and the metal layer is patterned to form a source and a drain electrodes. The etching stop layer can prevent the etchant to etch the active layer in the subsequent preparation of the source and the drain of the thin film transistor. However, one more photoresist process is the need in the patterning process of the etching stop layer of the conventional technology, so that the thin film transistor manufacturing process is more complicated.